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1.
Lab Chip ; 24(18): 4422-4439, 2024 09 10.
Article in English | MEDLINE | ID: mdl-39171671

ABSTRACT

Microfluidic systems combine multiple processing steps and components to perform complex assays in an autonomous fashion. To enable the integration of several bio-analytical processing steps into a single system, valving is used as a component that directs fluids and controls introduction of sample and reagents. While elastomer polydimethylsiloxane has been the material of choice for valving, it does not scale well to accommodate disposable integrated systems where inexpensive and fast production is needed. As an alternative to polydimethylsiloxane, we introduce a membrane made of thermoplastic elastomeric cyclic olefin copolymer (eCOC), that displays unique attributes for the fabrication of reliable valving. The eCOC membrane can be extruded or injection molded to allow for high scale production of inexpensive valves. Normally hydrophobic, eCOC can be activated with UV/ozone to produce a stable hydrophilic monolayer. Valves are assembled following in situ UV/ozone activation of eCOC membrane and thermoplastic valve seat and bonded by lamination at room temperature. eCOC formed strong bonding with polycarbonate (PC) and polyethylene terephthalate glycol (PETG) able to hold high fluidic pressures of 75 kPa and 350 kPa, respectively. We characterized the eCOC valves with mechanical and pneumatic actuation and found the valves could be reproducibly actuated >50 times without failure. Finally, an integrated system with eCOC valves was employed to detect minimal residual disease (MRD) from a blood sample of a pediatric acute lymphoblastic leukemia (ALL) patient. The two module integrated system evaluated MRD by affinity-selecting CD19(+) cells and enumerating leukemia cells via immunophenotyping with ALL-specific markers.


Subject(s)
Cycloparaffins , Elastomers , Polymers , Elastomers/chemistry , Cycloparaffins/chemistry , Polymers/chemistry , Temperature , Humans , Microfluidic Analytical Techniques/instrumentation
2.
Biomater Adv ; 163: 213934, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38954877

ABSTRACT

Sample partitioning is a crucial step towards digitization of biological assays on polymer microfluidic platforms. However, effective liquid filling into microwells and long-term hydrophilicity remain a challenge in polymeric microfluidic devices, impeding the applicability in diagnostic and cell culture studies. To overcome this, a method to produce permanent superhydrophilic 3-dimensional microwells using cyclic olefin copolymer (COC) microfluidic chips is presented. The COC substrate is oxidized using UV treatment followed by ultrasonic spray coating of polyvinyl alcohol solution, offering uniform and long-term coating of high-aspect ratio microfeatures. The coated COC surfaces are UV-cured before bonding with a hydrophobic pressure-sensitive adhesive to drive selective filling into the wells. The surface hydrophilicity achieved using this method remains unchanged (water contact angle of 9°) for up to 6 months and the modified surface is characterized for physical (contact angle & surface energy, morphology, integrity of microfeatures and roughness), chemical composition (FTIR, Raman spectroscopy) and coating stability (pH, temperature, time). To establish the feasibility of the modified surface in biological applications, PVA-coated COC microfluidic chips are tested for DNA sensing (digital LAMP detection of CMV), and biocompatibility through protein adsorption and cell culture studies (cell adhesion, viability, and metabolic activity). Kidney and breast cells remained viable for the duration of testing (7 days) on this modified surface, and the coating did not affect the protein content, morphology or quality of the cultured cells. The ultrasonic spray coated system, coating with 0.25 % PVA for 15 cycles with 0.12 A current after UV oxidation, increased the surface energy of the COC (naturally hydrophobic) from 22.04 to 112.89 mJ/m2 and improved the filling efficiency from 40 % (native untreated COC) to 94 % in the microwells without interfering with the biocompatibility of the surface, proving to be an efficient, high-throughput and scalable method of microfluidic surface treatment for diagnostic and cell growth applications.


Subject(s)
Cycloparaffins , Hydrophobic and Hydrophilic Interactions , Polyvinyl Alcohol , Polyvinyl Alcohol/chemistry , Humans , Cycloparaffins/chemistry , Surface Properties , Biocompatible Materials/chemistry , Polymers/chemistry , Cell Adhesion , Lab-On-A-Chip Devices , Feasibility Studies , Materials Testing/methods
3.
Biofabrication ; 16(4)2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38942007

ABSTRACT

The integration of acoustic wave micromixing with microfluidic systems holds great potential for applications in biomedicine and lab-on-a-chip technologies. Polymers such as cyclic olefin copolymer (COC) are increasingly utilized in microfluidic applications due to its unique properties, low cost, and versatile fabrication methods, and incorporating them into acoustofluidics significantly expands their potential applications. In this work, for the first time, we demonstrated the integration of polymer microfluidics with acoustic micromixing utilizing oscillating sharp edge structures to homogenize flowing fluids. The sharp edge mixing platform was entirely composed of COC fabricated in a COC-hydrocarbon solvent swelling based microfabrication process. As an electrical signal is applied to a piezoelectric transducer bonded to the micromixer, the sharp edges start to oscillate generating vortices at its tip, mixing the fluids. A 2D numerical model was implemented to determine the optimum microchannel dimensions for experimental mixing assessment. The system was shown to successfully mix fluids at flow rates up to 150µl h-1and has a modest effect even at the highest tested flow rate of 600µl h-1. The utility of the fabricated sharp edge micromixer was demonstrated by the synthesis of nanoscale liposomes.


Subject(s)
Cycloparaffins , Lab-On-A-Chip Devices , Liposomes , Liposomes/chemistry , Cycloparaffins/chemistry , Polymers/chemistry , Acoustics/instrumentation , Microfluidics/instrumentation , Microfluidics/methods , Microfluidic Analytical Techniques/instrumentation , Nanotechnology/instrumentation
4.
J Pharm Sci ; 113(9): 2947-2951, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38906251

ABSTRACT

In pharmaceutical freeze-drying processes, batch homogeneity is an important quality attribute. In this context, the edge-vial-effect is a challenging phenomenon. Shortly, this effect describes that vials at the edges of the shelf dry faster and at a higher temperature compared to vials in the middle of the shelf. Studies by Ehlers et al. revealed that this effect mainly origins from the number of neighbor vials cooling each other, which is reduced for vials in corners and edges compared to vials in the middle. Due to the reduced heat transfer in cyclic olefin polymer (COP) vials, the adverse edge-vial-effect should be greatly reduced allowing a better batch uniformity. In this focused study, glass and COP vials are compared regarding this effect on a fully loaded shelf. A reference experiment with vials placed at distance using a specially designed frame is presented as well.


Subject(s)
Cycloparaffins , Freeze Drying , Hot Temperature , Polymers , Freeze Drying/methods , Cycloparaffins/chemistry , Polymers/chemistry , Drug Packaging/methods , Glass/chemistry , Chemistry, Pharmaceutical/methods
5.
Int J Biol Macromol ; 271(Pt 1): 132550, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38782326

ABSTRACT

Cyclic olefin copolymer (COC) has emerged as an interesting biocompatible material for Organ-on-a-Chip (OoC) devices monitoring growth, viability, and metabolism of cells. Despite ISO 10993 approval, systematic investigation of bacteria grown onto COC is a still not documented issue. This study discusses biofilm formations of the canonical wild type BB120 Vibrio campbellii strain on a native COC substrate and addresses the impact of the physico-chemical properties of COC compared to conventional hydroxyapatite (HA) and poly(dimethylsiloxane) (PDMS) surfaces. An interdisciplinary approach combining bacterial colony counting, light microscopy imaging and advanced digital image processing remarks interesting results. First, COC can reduce biomass adhesion with respect to common biopolymers, that is suitable for tuning biofilm formations in the biological and medical areas. Second, remarkably different biofilm morphology (dendritic complex patterns only in the case of COC) was observed among the examined substrates. Third, the observed biofilm morphogenesis was related to the interaction of COC with the conditioning layer of the planktonic biological medium. Fourth, Level Co-occurrence Matrix (CGLM)-based analysis enabled quantitative assessment of the biomass textural fractal development under different coverage conditions. All of this is of key practical relevance in searching innovative biocompatible materials for pharmaceutical, implantable and medical products.


Subject(s)
Bacterial Adhesion , Biocompatible Materials , Biofilms , Vibrio , Biocompatible Materials/chemistry , Biofilms/drug effects , Biofilms/growth & development , Vibrio/drug effects , Vibrio/growth & development , Bacterial Adhesion/drug effects , Cycloparaffins/chemistry , Polymers/chemistry , Durapatite/chemistry , Biomass
6.
Chem Biodivers ; 21(6): e202400296, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38575390

ABSTRACT

1,3-Diheterocycloalkanes derivatives are important starting materials in fine organic synthesis. These compounds can be widely used in various fields such as industry, medicine, biotechnology and chemical technology. The paper is focused on synthesis and study of alkoxymethyl derivatives of diheterocycloalkanes (M1-M15) and inhibition effect on carbonic anhydrase and acetylcholinesterase. The structures of compounds were confirmed by 1H and 13C NMR spectroscopy. Also, in this study alkoxymethyl derivatives of diheterocycloalkanes were assessed for their influence on various metabolic enzymes, including acetylcholinesterase (AChE) and human carbonic anhydrase isoenzymes (hCA I and hCA II). The results demonstrated that all these compounds exhibited potent inhibitory effects on all the target enzymes, surpassing the standard inhibitors, as evidenced by their IC50 and Ki values. The Ki values for the compounds concerning AChE, hCA I, and hCA II enzymes were in the ranges of 1.02±0.17-8.38±1.02, 15.30±3.15-58.14±5.17 and 24.05±3.70-312.94±27.24 nM, respectively.


Subject(s)
Acetylcholinesterase , Carbonic Anhydrase II , Carbonic Anhydrase I , Carbonic Anhydrase Inhibitors , Cholinesterase Inhibitors , Cycloparaffins , Acetylcholinesterase/metabolism , Humans , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/pharmacology , Cholinesterase Inhibitors/chemistry , Carbonic Anhydrase Inhibitors/chemical synthesis , Carbonic Anhydrase Inhibitors/chemistry , Carbonic Anhydrase Inhibitors/pharmacology , Carbonic Anhydrase II/antagonists & inhibitors , Carbonic Anhydrase II/metabolism , Structure-Activity Relationship , Carbonic Anhydrase I/antagonists & inhibitors , Carbonic Anhydrase I/metabolism , Cycloparaffins/chemistry , Cycloparaffins/pharmacology , Cycloparaffins/chemical synthesis , Molecular Structure , Dose-Response Relationship, Drug
7.
J Hazard Mater ; 469: 133904, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38422739

ABSTRACT

The consumption of cycloalkanes is prevalent in low-temperature marine environments, likely influenced by psychrophilic microorganisms. Despite their significance, the primary active species responsible for marine cycloalkane degradation remain largely unidentified due to cultivation challenges. In this study, we provide compelling evidence indicating that the uncultured genus C1-B045 of Gammaproteobacteria is a pivotal participant in cycloalkane decomposition within China's marginal seas. Notably, the relative abundance of C1-B045 surged from 15.9% in the methylcyclohexane (MCH)-consuming starter culture to as high as 97.5% in MCH-utilizing extinction cultures following successive dilution-to-extinction and incubation cycles. We used stable isotope probing, Raman-activated gravity-driven encapsulation, and 16 S rRNA gene sequencing to link cycloalkane-metabolizing phenotype to genotype at the single-cell level. By annotating key enzymes (e.g., alkane monooxygenase, cyclohexanone monooxygenase, and 6-hexanolactone hydrolase) involved in MCH metabolism within C1-B045's representative metagenome-assembled genome, we developed a putative MCH degradation pathway.


Subject(s)
Cycloparaffins , Gammaproteobacteria , Humans , Gammaproteobacteria/genetics , Gammaproteobacteria/metabolism , Metagenome , China
8.
Nat Commun ; 15(1): 1122, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38321056

ABSTRACT

Gene therapies provide treatment options for many diseases, but the safe and long-term control of therapeutic transgene expression remains a primary issue for clinical applications. Here, we develop a muscone-induced transgene system packaged into adeno-associated virus (AAV) vectors (AAVMUSE) based on a G protein-coupled murine olfactory receptor (MOR215-1) and a synthetic cAMP-responsive promoter (PCRE). Upon exposure to the trigger, muscone binds to MOR215-1 and activates the cAMP signaling pathway to initiate transgene expression. AAVMUSE enables remote, muscone dose- and exposure-time-dependent control of luciferase expression in the livers or lungs of mice for at least 20 weeks. Moreover, we apply this AAVMUSE to treat two chronic inflammatory diseases: nonalcoholic fatty liver disease (NAFLD) and allergic asthma, showing that inhalation of muscone-after only one injection of AAVMUSE-can achieve long-term controllable expression of therapeutic proteins (ΔhFGF21 or ΔmIL-4). Our odorant-molecule-controlled system can advance gene-based precision therapies for human diseases.


Subject(s)
Alprostadil , Cycloparaffins , Mice , Humans , Animals , Alprostadil/metabolism , Transgenes , Cycloparaffins/metabolism , Odorants , Receptors, G-Protein-Coupled/metabolism , Dependovirus/genetics , Genetic Vectors
9.
Biotechnol J ; 19(2): e2300694, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38403410

ABSTRACT

Cycloalkanes have broad applications as specialty fuels, lubricants, and pharmaceuticals but are not currently available from renewable sources, whereas, production of microbial cycloalkanes such as cyclopropane fatty acids (CFA) has bottlenecks. Here, a systematic investigation was undertaken into the biosynthesis of CFA in Saccharomyces cerevisiae heterologously expressing bacterial CFA synthase. The enzyme catalyzes formation of a 3-membered ring in unsaturated fatty acids. Monounsaturated fatty acids in phospholipids (PL) are the site of CFA synthesis; precursor cis-Δ9 C16 and C18 fatty acids were enhanced through OLE1 and SAM2 overexpression which enhanced CFA in PL. CFA turnover from PL to storage in triacylglycerols (TAG) was achieved by phospholipase PBL2 overexpression and acyl-CoA synthase to increase flux to TAG. Consequently, CFA storage as TAG reached 12 mg g-1 DCW, improved 3-fold over the base strain and >22% of TAG was CFA. Our research improves understanding of cycloalkane biosynthesis in yeast and offers insights into processing of other exotic fatty acids.


Subject(s)
Cycloparaffins , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genetics , Fatty Acids , Cyclopropanes , Phospholipids , Triglycerides
10.
Biochem Biophys Res Commun ; 702: 149628, 2024 04 02.
Article in English | MEDLINE | ID: mdl-38335704

ABSTRACT

Atherosclerosis (AS) is considered to be one of the main pathogenic factors of coronary heart disease, cerebral infarction and peripheral vascular disease. Oxidative stress and inflammation run through the occurrence and development of atherosclerosis and related cardiovascular events. Muscone is a natural extract of deer musk and also the main physiological active substance of musk. This study investigated the impact of muscone on atherosclerosis. ApoE-/- mice were used to establised AS model and injected with low-dose (4 mg/kg/day) or high-dose (8 mg/kg/day) of muscone intraperitoneally for 4 weeks. Then aortic tissues were collected, and pathological sections of the aorta were prepared for oil red staining, HE and masson staining. The changes of MDA, SOD, VCAM-1, NF-κB, and TNF-α were observed by Western blotting or immunofluorescence staining. The results showed that high-dose muscone could effectively reduce the plaque area/aortic root area and relative atherosclerotic area, reduce the collagen composition in plaque tissue. In addition, we also found that high-dose muscone can effectively increase MDA level, reduce the level of SOD, and inhibit the expression of VCAM-1, NF-κB/p65, TNF-α in arterial plaques. Our results indicate that the administration of muscone has the benefit of inhibiting atherosclerosis. The potential mechanisms may be associated with antioxidant effect and inhibition of inflammatory reaction in arterial plaques. With the increasing understanding of the relationship between muscone and atherosclerosis, muscone has high potential value as a new drug to treat atherosclerosis.


Subject(s)
Atherosclerosis , Cycloparaffins , Deer , Plaque, Atherosclerotic , Mice , Animals , Plaque, Atherosclerotic/pathology , NF-kappa B/metabolism , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/metabolism , Mice, Knockout, ApoE , Deer/metabolism , Atherosclerosis/metabolism , Inflammation/pathology , Aorta/metabolism , Superoxide Dismutase/metabolism , Apolipoproteins E/metabolism
11.
Exp Neurol ; 373: 114678, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38185313

ABSTRACT

As the main bioactive component of musk, muscone has been reported to have marked protective effects in treating acute ischemic stroke (AIS). However, the specific anti-stroke mechanism of muscone still needs further research. In the current investigation, the PC12 cells OGD/R and the rat transient MCAO/R models were utilized as the AIS models. Serum hepatic and renal functional indexes (ALT, AST, BUN, and Cr) and cell viability were determined to select the appropriate muscone concentrations for in vitro and in vivo experiments. TTC, Hematoxylin and eosin (H&E), and Live/Dead staining were utilized to evaluate the protective effects of muscone in injured tissues and cells. Western blotting analysis, TUNEL staining, propidium iodide, and annexin V staining were applied to detect the anti-apoptotic effect of muscone. Double-label immunofluorescence staining of T-cell intracellular antigen-1 (TIA1) and Ras-GAP SH3 domain-binding protein 1 (G3BP1) was performed to observe whether muscone regulated the SG formation level. Molecular docking, TIA1 silencing and TIA1 overexpression experiments were employed to investigate the molecular mechanism underlying the regulation of SG formation by muscone. The 2, 3, 5-Triphenyl-tetrazolium chloride (TTC) staining and live/dead staining showed the AIS injury level of MCAO/R rat and the OGD/R PC12 cells were attenuated by muscone administration. The muscone significantly minimized the apoptosis rate in MCAO/R rats and OGD/R PC12 cells following flow cytometry analysis, western blotting analysis, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The double-label immunofluorescence staining data revealed that muscone promoted the SG formation level in OGD/R PC12 cells and the cortex MCAO/R rats. The results of molecular docking, TIA1 silencing and TIA1 overexpression experiments revealed that muscone could bind to TIA1 protein and regulate its expression level, thereby promoting the formation of stress granules and exerting a protective effect against AIS injury. This study indicated that the significant protective effect of muscone in reducing apoptosis levels might be via promoting SG formation under AIS conditions. This study further explores the therapeutic effect and anti-apoptosis mechanism of muscone in AIS, which may provide a potential candidate drug for the clinical treatment of AIS injury.


Subject(s)
Brain Ischemia , Cycloparaffins , Ischemic Stroke , Reperfusion Injury , Stroke , Rats , Animals , Ischemic Stroke/drug therapy , DNA Helicases , Molecular Docking Simulation , Stress Granules , Poly-ADP-Ribose Binding Proteins , RNA Helicases , RNA Recognition Motif Proteins , Apoptosis , Stroke/drug therapy , Reperfusion Injury/drug therapy , Brain Ischemia/drug therapy , Brain Ischemia/metabolism
12.
Pharm Res ; 41(1): 51-62, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37989952

ABSTRACT

INTRODUCTION: Medical syringes are widely used in hospitals to store and administer drugs, and the contact time between the drugs and these syringes can vary from a few minutes to several weeks like for pharmaceutical preparations. The aim of this comparative study was to evaluate the potential sorption phenomena occurring between three drugs (paracetamol, diazepam and insulin aspart) and polypropylene syringes (PP) or syringes made of Cyclic Olefin Copolymer (COC). MATERIALS AND METHODS: 50 mL 3-part syringes made of either COC with crosslinked silicone on the barrel inner surface (COC-CLS) and a bromobutyl plunger seal, or PP lubricated with silicone oil (PP-SOL) with a polyisoprene plunger seal were used. RESULTS: COC-CLS syringes induced less sorption of diazepam and insulin than PP-SOL syringes and the plunger seal material seemed to be the main cause of these interactions. An alkalinization of the medications in contact with the PP-SOL syringes was observed. It could be caused by leachable compounds and should be investigated further. CONCLUSION: This work shows once again that it is essential to consider content-container interactions to help improve the safe use of parenteral drugs.


Subject(s)
Cycloparaffins , Polypropylenes , Syringes , Polymers , Silicone Oils , Pharmaceutical Preparations , Diazepam
13.
Chemosphere ; 349: 140900, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38065261

ABSTRACT

Management of growing volumes of fluid fine tailings (FFT) is a significant challenge for oil sands industry. A potential alternative non-aqueous solvent extraction (NAE) process uses cycloalkane solvent such as cyclohexane or cyclopentane with very little water and generates smaller volumes of 'dry' solids (NAES) with residual solvent. Here we investigate remediation of NAES in a simulated bench-scale upland reclamation scenario. In the first study, microcosms with nutrient medium plus FFT as inoculum were amended with cyclohexane and incubated for ∼1 year, monitoring for cyclohexane biodegradation under aerobic conditions. Biodegradation of cyclohexane occurred under aerobic conditions with no metabolic intermediates detected. A second study using NAES mixed with FFT spiked with cyclohexane and cyclopentane, with or without additional nutrients (nitrogen and phosphorus), showed complete and rapid aerobic biodegradation of both cycloalkanes in NAES inoculated with FFT and supplemented with nutrients. 16S rRNA gene sequencing revealed dominance of Rhodoferax and members of Burkholderiaceae during aerobic cyclohexane biodegradation in FFT, and Hydrogenophaga, Acidovorax, Defluviimonas and members of Porticoccaceae during aerobic biodegradation of cyclohexane and cyclopentane in NAES inoculated with FFT and supplemented with nutrients. The findings indicate that biodegradation of cycloalkanes from NAES is possible under aerobic condition, which will contribute to the successful reclamation of oil sands tailings for land closure.


Subject(s)
Cycloparaffins , Oil and Gas Fields , RNA, Ribosomal, 16S , Cyclohexanes , Cyclopentanes , Biodegradation, Environmental , Solvents
14.
Article in English | MEDLINE | ID: mdl-38083392

ABSTRACT

In this work, a fabrication process for implantable electrodes using a Cyclic Olefin Copolymer (COC) substrate and a SU-8 passivation layer was presented. COC and SU-8 were shown to be suitable for implantable neural electrodes due to their biocompatibility, chemical resistance, and thermal stability. The electrodes were successfully patterned on the COC film, and the SU-8 passivation layer was coated while maintaining site-opened via photolithography. The photocrosslinking lamination of the substrate and passivation layer was used to produce electrodes with fine line widths of 20um without applying heat.


Subject(s)
Cycloparaffins , Microelectrodes , Electrodes, Implanted
15.
Article in English | MEDLINE | ID: mdl-38083447

ABSTRACT

A retinal prosthesis is a device that can provide artificial vision to people who have lost their sight from certain retinal disorder. Because the device needs to be inserted into the body, high flexibility and reliability is required. Recently, devices using thermoplastic polymers such as LCP and COC as substrates have been studied. Being a highly functional integrated device, retinal prosthesis poses many design challenges. Among them, the stimulation chip embedding can be a particularly important task. Although it is common to use a wire bonding method for chip embedding, there are several limitations that are difficult to apply to implantable device. In this investigation, a novel approach is developed for high spaceefficient electrical connections and perform reliable encapsulation of integrated circuits to replace wire bonding. Since designing and manufacturing the stimulator chip used in retinal prosthesis requires non-negligible cost, a silicon die with the identical shape was selected as a substitute for testing purposes.


Subject(s)
Cycloparaffins , Retinal Diseases , Visual Prosthesis , Humans , Reproducibility of Results , Polymers
16.
Ecotoxicol Environ Saf ; 268: 115695, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37976932

ABSTRACT

Widespread use of spray-type consumer products can raise significant concerns regarding their effects on indoor air quality and human health. In this study, we conducted non-target screening using gas chromatography-mass spectrometry (GC-MS) to analyze VOCs in 48 different spray-type consumer products. Using this approach, we tentatively identified a total of 254 VOCs from the spray-type products. Notably, more VOCs were detected in propellant-type products which are mostly solvent-based than in trigger-type ones which are mostly water-based. The VOCs identified encompass various chemical classes including alkanes, cycloalkanes, monoterpenoids, carboxylic acid derivatives, and carbonyl compounds, some of which arouse concerns due to their potential health effects. Alkanes and cycloalkanes are frequently detected in propellant-type products, whereas perfumed monoterpenoids are ubiquitous across all product categories. Among the identified VOCs, 12 compounds were classified into high-risk groups according to detection frequency and signal-to-noise (S/N) ratio, and their concentrations were confirmed using reference standards. Among the identified VOCs, D-limonene was the most frequently detected compound (freq. 21/48), with the highest concentration of 1.80 mg/g. The risk assessment was performed to evaluate the potential health risks associated with exposure to these VOCs. The non-carcinogenic and carcinogenic risks associated with the assessed VOC compounds were relatively low. However, it is important not to overlook the risk faced by occupational exposure to these VOCs, and the risk from simultaneous exposure to various VOCs contained in the products. This study serves as a valuable resource for the identification of unknown compounds in the consumer products, facilitating the evaluation of potential health risks to consumers.


Subject(s)
Air Pollutants , Cycloparaffins , Volatile Organic Compounds , Humans , Air Pollutants/analysis , Volatile Organic Compounds/toxicity , Volatile Organic Compounds/analysis , Cycloparaffins/analysis , Alkanes/analysis , Monoterpenes/analysis , Environmental Monitoring/methods
17.
Acta Crystallogr D Struct Biol ; 79(Pt 10): 944-952, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37747292

ABSTRACT

Over the past two decades, serial X-ray crystallography has enabled the structure determination of a wide range of proteins. With the advent of X-ray free-electron lasers (XFELs), ever-smaller crystals have yielded high-resolution diffraction and structure determination. A crucial need to continue advancement is the efficient delivery of fragile and micrometre-sized crystals to the X-ray beam intersection. This paper presents an improved design of an all-polymer microfluidic `chip' for room-temperature fixed-target serial crystallography that can be tailored to broadly meet the needs of users at either synchrotron or XFEL light sources. The chips are designed to be customized around different types of crystals and offer users a friendly, quick, convenient, ultra-low-cost and robust sample-delivery platform. Compared with the previous iteration of the chip [Gilbile et al. (2021), Lab Chip, 21, 4831-4845], the new design eliminates cleanroom fabrication. It has a larger imaging area to volume, while maintaining crystal hydration stability for both in situ crystallization or direct crystal slurry loading. Crystals of two model proteins, lysozyme and thaumatin, were used to validate the effectiveness of the design at both synchrotron (lysozyme and thaumatin) and XFEL (lysozyme only) facilities, yielding complete data sets with resolutions of 1.42, 1.48 and 1.70 Å, respectively. Overall, the improved chip design, ease of fabrication and high modifiability create a powerful, all-around sample-delivery tool that structural biologists can quickly adopt, especially in cases of limited sample volume and small, fragile crystals.


Subject(s)
Cycloparaffins , Muramidase , Crystallography , Muramidase/chemistry , Microfluidics/methods , Temperature , Equipment Design , Crystallography, X-Ray , Proteins , Polymers
18.
Macromol Rapid Commun ; 44(23): e2300318, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37572085

ABSTRACT

It is an urgent need to develop efficient solid state cooling technologies and materials with high cycle life. Poly-p-phenylene benzodioxole (PBO) is a high performance fiber with excellent mechanical properties. In this work, for the first time, elasto- and twistocaloric cooling of PBO fibers by stretching and twisting of the PBO fiber bundles is reported. The cooling temperature reaches -0.4 and -1.3 K, for fiber stretching and twisting, respectively. A self-coiled PBO fiber achieves maximum cooling of -3.7 K upon stretching by 35% strain, with an exceptionally high cycle life of 200 000 times. During the twisting of the PBO fibers, reversible changes in the intensity of the diffraction peaks in X-ray diffraction patterns are observed. A strain-sensitive color change application is realized by coating a self-coiled PBO fiber with liquid crystallite dyes. This work provides new perspectives for PBO fibers as a high cycle-life solid-state refrigeration material.


Subject(s)
Cycloparaffins , Heterocyclic Compounds , Cold Temperature , Temperature , Benzodioxoles
19.
Environ Microbiol ; 25(12): 2958-2971, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37599091

ABSTRACT

Cycloalkanes are abundant and toxic compounds in subsurface petroleum reservoirs and their fate is important to ecosystems impacted by natural oil seeps and spills. This study focuses on the microbial metabolism of methylcyclohexane (MCH) and methylcyclopentane (MCP) in the deep Gulf of Mexico. MCH and MCP are often abundant cycloalkanes observed in petroleum and will dissolve into the water column when introduced at the seafloor via a spill or natural seep. We conducted incubations with deep Gulf of Mexico (GOM) seawater amended with MCH and MCP at four stations. Within incubations with active respiration of MCH and MCP, we found that a novel genus of bacteria belonging to the Porticoccaceae family (Candidatus Reddybacter) dominated the microbial community. Using metagenome-assembled genomes, we reconstructed the central metabolism of Candidatus Reddybacter, identifying a novel clade of the particulate hydrocarbon monooxygenase (pmo) that may play a central role in MCH and MCP metabolism. Through comparative analysis of 174 genomes, we parsed the taxonomy of the Porticoccaceae family and found evidence suggesting the acquisition of pmo and other genes related to the degradation of cyclic and branched hydrophobic compounds were likely key events in the ecology and evolution of this group of organisms.


Subject(s)
Cycloparaffins , Gammaproteobacteria , Microbiota , Petroleum Pollution , Petroleum , Geologic Sediments/microbiology , Hydrocarbons/metabolism , Seawater/microbiology , Gammaproteobacteria/genetics , Petroleum/metabolism , Gulf of Mexico , Biodegradation, Environmental
20.
Org Lett ; 25(24): 4551-4555, 2023 Jun 23.
Article in English | MEDLINE | ID: mdl-37306259

ABSTRACT

An enantioselective intermolecular [3 + 2] cycloaddition of N-arylcyclopropylamines with 2-aryl acrylates/ketones and cyclic ketone-derived terminal olefins via asymmetric photoredox catalysis is reported. A dual catalyst system involving DPZ and a chiral phosphoric acid is effective for the transformations, leading to a wide array of valuable cyclopentylamines with high yields, ee's, and drs. Among them, elaborate modulation of the ester group of 2-aryl acrylates was shown to be effective in improving reactivity, thereby enabling the success of the transformations.


Subject(s)
Alkenes , Cycloparaffins , Electrons , Stereoisomerism , Catalysis , Ketones , Acrylates
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